• Anomalies of Discrete Gauge Symmetries and their Cancellation in 6D F-theory

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    Swampland Seminar Speaker: Paul-Konstantin Oehlmann(Northeastern) Title: Anomalies of Discrete Gauge Symmetries and their Cancellation in 6D F-theory Abstract: We consider 6D SUGRAs with a discrete gauge group G, engineered via F-theory compactifications on genus-one fibered threefolds. We argue that group G suffers from Dai-Freed anomalies that can be canceled via a discrete Green-Schwarz mechanism. We comment […]

  • Unorientable Quantum Field Theories: From crosscaps to holography

    Virtual

    https://www.youtube.com/watch?v=0y2colQwY34 Quantum Matter Seminar Speaker: João Caetano (CERN) Title: Unorientable Quantum Field Theories: From crosscaps to holography Abstract: In two dimensions, one can study quantum field theories on unorientable manifolds by introducing crosscaps. This defines a class of states called crosscap states which share a few similarities with the notion of boundary states. In this talk, I […]

  • Kähler bands—Chern insulators, holomorphicity and induced quantum geometry

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/2BF5q6d_Zo4 Topological Quantum Matter Seminar Speaker: Bruno Mera, Tohoku University Title: Kähler bands—Chern insulators, holomorphicity and induced quantum geometry Abstract: The notion of topological phases has dramatically changed our understanding of insulators. There is much to learn about a band insulator beyond the assertion that it has a gap separating the valence bands from the conduction […]

  • Clique listing algorithms

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    Speaker: Virginia Vassilevska Williams (MIT) Title: Clique listing algorithms Abstract: A k-clique in a graph G is a subgraph of G on k vertices in which every pair of vertices is linked by an edge. Cliques are a natural notion of social network cohesiveness with a long history. A fundamental question, with many applications, is […]

  • From Engine to Auto

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/h3jcSg359E8 New Technologies in Mathematics Seminar Speakers: João Araújo, Mathematics Department, Universidade Nova de Lisboa and Michael Kinyon, Department of Mathematics, University of Denver Title: From Engine to Auto Abstract: Bill McCune produced the program EQP that deals with first order logic formulas and in 1996 managed to solve Robbins' Conjecture. This very powerful tool reduces […]

  • Gravitational Wave, Angular Momentum, and Supertranslation Ambiguity

    Virtual

    General Relativity Seminar Speaker: Naqing Xie (Fudan University) Title: Gravitational Wave, Angular Momentum, and Supertranslation Ambiguity Abstract: The supertranslation ambiguity of angular momentum is a long-standing and conceptually important issue in general relativity. Recently, there appeared the first definition of angular momentum at null infinity that is supertranslation invariant. However, in the compact binary coalescence community, supertranslation […]

  • 2-Categories and the Massive 3d A-Model

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    Algebraic Geometry in String Theory Seminar Speaker: Ahsan Khan, IAS Title: 2-Categories and the Massive 3d A-Model Abstract: I will outline the construction of a 2-category associated to a hyperKahler moment map. The construction is based on partial differential equations in one, two, and three dimensions combined with a three-dimensional version of the Gaiotto-Moore-Witten web formalism. […]

  • Some non-concave dynamic optimization problems in finance

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    Member Seminar Speaker: Shuaijie Qian (Harvard CMSA) Title: Some non-concave dynamic optimization problems in finance Abstract: Non-concave dynamic optimization problems appear in many areas of finance and economics. Most of existing literature solves these problems using the concavification principle, and derives equivalent, concave optimization problems whose value functions are still concave. In this talk, I will present […]

  • Kardar-Parisi-Zhang dynamics in integrable quantum magnets

    Virtual

    Quantum Matter Seminar Speaker: Francisco Machado  (Berkeley/Harvard) Title: Kardar-Parisi-Zhang dynamics in integrable quantum magnets Abstract: Although the equations of motion that govern quantum mechanics are well-known, understanding the emergent macroscopic behavior that arises from a particular set of microscopic interactions remains remarkably challenging. One particularly important behavior is that of hydrodynamical transport; when a quantum system has a […]

  • Optical axion electrodynamics

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/T1x60gYry4I Topological Quantum Matter Seminar Speaker: Junyeong Ahn (Harvard) Title: Optical axion electrodynamics Abstract: Electromagnetic fields in a magneto-electric medium behave in close analogy to photons coupled to the hypothetical elementary particle, the axion. This emergent axion electrodynamics is expected to provide novel ways to detect and control material properties with electromagnetic fields. Despite having […]

  • Doping and inverting Mott insulators on semiconductor moire superlattices

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/-NisBM-2a2I Speaker: Liang Fu (MIT) Title: Doping and inverting Mott insulators on semiconductor moire superlattices Abstract: Semiconductor bilayer heterostructures provide a remarkable platform for simulating Hubbard models on an emergent lattice defined by moire potential minima. As a hallmark of Hubbard model physics, the Mott insulator state with local magnetic moments has been observed at […]

  • Asymptotic geometry of null hypersurface in Schwarzschild spacetime and null Penrose inequality

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/pHDcEX45YKM General Relativity Seminar Speaker: Pengyu Le (BIMSA) Title: Asymptotic geometry of null hypersurface in Schwarzschild spacetime and null Penrose inequality Abstract: Null Penrose inequality is an important case of the well-known Penrose inequality on a null hypersurface. It conjectures the relation between the area of the outmost marginally trapped surface and the Bondi mass at […]